There has been widely used a seat that has a seat cushion serving as a seat (stool) when a person is seated and a seat back serving as a backrest when a person is seated. It is known to collect information showing a relationship between a vehicle and a behavior of a human body during vehicle collision by mounting a mannequin on a vehicle including such seat (see JP-A-2013-257287). In the mannequin disclosed in JP-A-2013-257287, it is possible to reproduce the typical behavior of the human body during vehicle collision by reproducing one typical body shape. Therefore, various information during vehicle collision can be collected by using this mannequin.
Unlike such information during vehicle collision, there has been developed a mannequin that is used for collecting information serving as an index of the comfort of the seat (see US-A1-2009/0025492 and JP-A-2014-61161). The mannequin disclosed in US-A1-2009/0025492 is a mannequin where the position of the spinal column can be adjusted. In this mannequin, a rod is disposed between a shoulder and a pelvis and the movement range of the spinal column is restricted. The mannequin disclosed in JP-A-2014-61161 is made in consideration of the fact that there are personal differences in the comfortable posture. This mannequin is configured so that a plurality of types of comfortable postures can be expressed by changing the setting of one mannequin. When the characteristics of each individual's desired posture and the shape of the seat are not suited, this condition is reflected to the seating pressure distribution or the posture. Therefore, the information relating to this condition is collected and the collected information can be used as the material for examining the comfort or the like of the seat. As disclosed in JP-A-2014-61161, the mannequin used for collecting such information is configured so that the shape of the mannequin follows the shape of the seat to some extent.
The mannequin disclosed in JP-A-2013-257287 is not intended to be used for examining the comfort or the like of the seat. Therefore, although the shape of the mannequin placed on the seat can be changed in accordance with the shape of the seat, the mannequin is not configured so that it can perform the adjustment to maintain the comfortable posture. Since the mannequin disclosed in US-A1-2009/0025492 is configured so that a shoulder and a pelvis are fixed by a rod, a pelvic part and a chest part are not configured so as to be relatively movable. The mannequin disclosed in JP-A-2014-61161 is intended to be used for examining the comfort or the like of the seat. Therefore, this mannequin is configured so that it is deformable so as to lean against the seat. This mannequin is intended to be used in the state where the portion corresponding to the vicinity of the thorax of the human body leans against the seat back. Therefore, when a portion of a lumbar spine is bent, and thus, the chest part is spaced away from the seat back, an upper body of the mannequin may fall toward a thigh part, as indicated by a two-dot chain line in FIG. 2. Although there is no problem in this configuration in a case where the chest part of the mannequin leans against the seat back, the seating posture of the human body may be different from this posture. For example, in order to reduce the burden for maintaining the head part, it is conceivable for a seating person to sit on the seat in such a way that the vicinity of the thorax is not abutted against the seat back but only the vicinity of the pelvis of the seating person is abutted against the seat back. In the mannequin disclosed in JP-A-2014-61161, it is difficult to express such seating posture.